On Wed, 13 May 2009, Flavien Lambert wrote:

> Dear all, I didn't use ConTeXt for some time and, so, have just re-installed
> the minimals tonight. When running on some of my files, Mark II does its job
> well but Mark IV tells me
>
> error: Invalid field id nucleus for node type choice (0)
> .
> l.133 ... M décrit l'axe $({\rm O};\vect{e_{x}})$
>                                                   avec une vitesse
> $\dot{x}...
>
> I have absolutely no idea what it is trying to say to me...
> If related, the macro is defined by
> \def\vect#1{%
>  \overrightarrow{#1}
> }

Can you create a minimum example. This runs fine here

\def\vect#1{%
   \overrightarrow{#1}}

\starttext
$\vect{e_{x}}$
\stoptext

Using ConTeXt  ver: 2009.05.12 22:35 MKIV

Aditya